Buggy code:
public void addMouseListener ( MouseListener listener ) { } public void addMouseTrackListener ( MouseTrackListener listener ) { } public void addMouseMoveListener ( MouseMoveListener listener ) { } public void addMouseWheelListener ( MouseWheelListener listener ) { } void addRelation ( Control control ) { } public void addPaintListener ( PaintListener listener ) { } public void addTraverseListener ( TraverseListener listener ) { } boolean becomeFirstResponder ( int id , int sel ) { } void checkBackground ( ) { } void checkBuffered ( ) { } public Point computeSize ( int wHint , int hHint ) { } public Point computeSize ( int wHint , int hHint , boolean changed ) { } Control computeTabGroup ( ) { } Control [ ] computeTabList ( ) { } Control computeTabRoot ( ) { } NSView contentView ( ) { } void createWidget ( ) { } Color defaultBackground ( ) { } Font defaultFont ( ) { } Color defaultForeground ( ) { } NSFont defaultNSFont ( ) { } void deregister ( ) { } void destroyWidget ( ) { } void doCommandBySelector ( int id , int sel , int selector ) { } public boolean dragDetect ( Event event ) { } public boolean dragDetect ( MouseEvent event ) { } boolean dragDetect ( int button , int count , int stateMask , int x , int y ) { } boolean dragDetect ( int x , int y , boolean filter , boolean [ ] consume ) { } boolean drawGripper ( int x , int y , int width , int height , boolean vertical ) { } void drawWidget ( int id , NSGraphicsContext context , NSRect rect , boolean sendPaint ) { } void enableWidget ( boolean enabled ) { } NSView eventView ( ) { } void fillBackground ( NSView view , NSGraphicsContext context , NSRect rect , int imgHeight ) { } Cursor findCursor ( ) { } Control findBackgroundControl ( ) { } Menu [ ] findMenus ( Control control ) { } void fixChildren ( Shell newShell , Shell oldShell , Decorations newDecorations , Decorations oldDecorations , Menu [ ] menus ) { } void fixFocus ( Control focusControl ) { } void flagsChanged ( int id , int sel , int theEvent ) { } NSView focusView ( ) { } public boolean forceFocus ( ) { } public Accessible getAccessible ( ) { } public Color getBackground ( ) { } Color getBackgroundColor ( ) { } public Image getBackgroundImage ( ) { } public int getBorderWidth ( ) { } public Rectangle getBounds ( ) { } public boolean getDragDetect ( ) { } int getDrawCount ( ) { } public Cursor getCursor ( ) { } public boolean getEnabled ( ) { } public Font getFont ( ) { } public Color getForeground ( ) { } Color getForegroundColor ( ) { } public Object getLayoutData ( ) { } public Point getLocation ( ) { } public Menu getMenu ( ) { } int getMininumHeight ( ) { } public Monitor getMonitor ( ) { } public Composite getParent ( ) { } Control [ ] getPath ( ) { } NSBezierPath getPath ( Region region ) { } public Region getRegion ( ) { } public Shell getShell ( ) { } public Point getSize ( ) { } float getThemeAlpha ( ) { } public String getToolTipText ( ) { } public boolean getVisible ( ) { } boolean hasBorder ( ) { } boolean hasFocus ( ) { } int hitTest ( int id , int sel , NSPoint point ) { if ( ( ( state ) & ( DISABLED ) ) != 0 ) return 0 ; <START_BUG> if ( isActive ( ) ) <END_BUG> return 0 ; if ( ( regionPath ) != null ) { NSPoint pt = view . superview ( ) . convertPoint_toView_ ( point , view ) ; return regionPath . containsPoint ( pt ) ? view . id : 0 ; } return super . hitTest ( id , sel , point ) ; } boolean insertText ( int id , int sel , int string ) { } public int internal_new_GC ( GCData data ) { } public void internal_dispose_GC ( int context , GCData data ) { } boolean isActive ( ) { } boolean isDescribedByLabel ( ) { } public boolean isEnabled ( ) { } boolean isEnabledCursor ( ) { } boolean isFocusAncestor ( Control control ) { } public boolean isFocusControl ( ) { } public boolean isReparentable ( ) { } boolean isShowing ( ) { } boolean isTabGroup ( ) { } boolean isTabItem ( ) { } boolean isTrim ( NSView view ) { } public boolean isVisible ( ) { } void keyDown ( int id , int sel , int theEvent ) { } void keyUp ( int id , int sel , int theEvent ) { } void markLayout ( boolean changed , boolean all ) { } int menuForEvent ( int id , int sel , int theEvent ) { } Decorations menuShell ( ) { } void scrollWheel ( int id , int sel , int theEvent ) { } boolean mouseEvent ( int id , int sel , int theEvent , int type ) { } void mouseDown ( int id , int sel , int theEvent ) { } void mouseUp ( int id , int sel , int theEvent ) { } void mouseMoved ( int id , int sel , int theEvent ) { } void mouseDragged ( int id , int sel , int theEvent ) { } void rightMouseDown ( int id , int sel , int theEvent ) { } void rightMouseUp ( int id , int sel , int theEvent ) { } void rightMouseDragged ( int id , int sel , int theEvent ) { }

Fix:
if ( ! ( isActive ( ) ) )